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In this work, a new compact sixth order accurate finite difference scheme for the two and three-dimensional Helmholtz equation is presented. The main significance of the proposed scheme is that its sixth order leading truncation error term…

Numerical Analysis · Mathematics 2024-09-23 Neelesh Kumar , Ritesh Kumar Dubey

Dimensionality serves as an indispensable ingredient in any attempt to formulate the low-dimensional physics, and studying the dimensional crossover at a fundamental level is challenging. The purpose of this work is to study the…

Quantum Gases · Physics 2022-11-22 KangKang Li , Zhaoxin Liang

Metamaterial cloaking has been proposed and studied in recent years following several interesting approaches. One of them, the scattering-cancellation technique, or plasmonic cloaking, exploits the plasmonic effects of suitably designed…

Classical Physics · Physics 2015-05-19 Andrea Alu , David Rainwater , Aaron Kerkhoff

Absorbing layers are sometimes required to be impractically thick in order to offer an accurate approximation of an absorbing boundary condition for the Helmholtz equation in a heterogeneous medium. It is always possible to reduce an…

Numerical Analysis · Mathematics 2014-08-15 Rosalie Bélanger-Rioux

In this paper we formulate the problem of elastodynamic transformation cloaking for Kirchhoff-Love plates and elastic plates with both the in-plane and out-of-plane displacements. A cloaking transformation maps the boundary-value problem of…

Soft Condensed Matter · Physics 2020-11-16 Ashkan Golgoon , Arash Yavari

It is shown how a recently proposed method of cloaking is effective over a broad range of frequencies. The method is based on three or more active devices. The devices, while not radiating significantly, create a ``quiet zone'' between the…

Mathematical Physics · Physics 2015-06-03 Fernando Guevara Vasquez , Graeme W. Milton , Daniel Onofrei

The diffuse-domain, or smoothed boundary, method is an attractive approach for solving partial differential equations in complex geometries because of its simplicity and flexibility. In this method the complex geometry is embedded into a…

Numerical Analysis · Mathematics 2019-12-02 Fei Yu , Zhenlin Guo , John Lowengrub

We propose an analytic perturbative scheme for determining the eigenvalues of the Helmholtz equation, $(\nabla^2 + k^2) \psi = 0$, in three dimensions with an arbitrary boundary where $\psi$ satisfies either the Dirichlet boundary condition…

Mathematical Physics · Physics 2012-12-10 S. Panda , G. Hazra

We propose a fast method for high order approximation of potentials of the Helmholtz type operator Delta+kappa^2 over hyper-rectangles in R^n. By using the basis functions introduced in the theory of approximate approximations, the cubature…

Numerical Analysis · Mathematics 2019-10-29 Flavia Lanzara , Vladimir Maz'ya , Gunther Schmidt

The focus of this paper is to show the absence of critical points for the solutions to the Helmholtz equation in a bounded domain $\Omega\subset\mathbb{R}^{3}$, given by \[ \left\{ \begin{array}{l} -\rm{div}(a\,\nabla u_{\omega}^{g})-\omega…

Analysis of PDEs · Mathematics 2016-09-07 Giovanni S. Alberti

Light diffraction at an aperture is a basic problem that has generated a tremendous amount of interest in optics. Some of the most significant diffraction results are the Fresnel-Kirchhoff and Rayleigh-Sommerfeld formulas. These theories…

Optics · Physics 2022-02-09 Neha Goswami , Gabriel Popescu

The behavior of atomic H in a semi-bounded space $z \geq 0$ with the condition of "not going through" the boundary (the surface $z=0$) for the electronic wavefunction (WF) is considered. It is shown that in a wide range of "not going…

Atomic Physics · Physics 2019-01-29 S. Artyukova , K. Sveshnikov , A. Tolokonnikov

Invisibility cloaking not only catches the human imagination, but also promises fascinating applications in optics and photonics. By manipulating electromagnetic waves with metamaterials, researchers have been able to realize…

Electromagnetic invisible devices usually designed by transformation optics are rather complicated in material parameters and not suitable for general applications. Recently a topology optimized cloak based on level-set method was proposed…

Optics · Physics 2015-06-17 Lu Lan , Fei Sun , Yichao Liu , C. K. Ong , Yungui Ma

Simulational studies of spin glasses in the last decade have focussed on the so-called replicon exponent $\alpha$ as a means of determining whether the low-temperature phase of spin glasses is described by the replica symmetry breaking…

Disordered Systems and Neural Networks · Physics 2021-06-08 M. A. Moore

We demonstrate three simple cloaking devices that can hide very large spatial objects over the entire visible spectrum using only passive, off-the-shelf optics. The cloaked region for all of the devices exceeds 10^6 mm3 with the largest…

Optics · Physics 2015-06-16 John C. Howell , J. Benjamin Howell

Based on electromagnetic and acoustic transformation theory, a new strategy has been presented in this article to implement double invisibility cloaking, which has not been done yet. By applying a combination of four conventional cloaking…

Applied Physics · Physics 2019-12-02 Hasanpour Tadi Saeed , Shokri Babak

Cloaking using complementary media was suggested by Lai et al. in [8]. The study of this problem faces two difficulties. Firstly, this problem is unstable since the equations describing the phenomenon have sign changing coefficients, hence…

Analysis of PDEs · Mathematics 2015-07-08 Hoai-Minh Nguyen

We first review classical results on cloaking and mirage effects for electromagnetic waves. We then show that transformation optics allows the masking of objects or produces mirages in diffusive regimes. In order to achieve this, we…

A class of high-order shock-capturing schemes, P$_n$T$_m$-BVD (Deng et al., J. Comp. Phys., 386:323-349, 2019; Comput. & Fluids, 200:104433, 2020.) schemes, have been devised to solve the Euler equations with substantially reduced numerical…

Numerical Analysis · Mathematics 2021-06-04 Hiro Wakimura , Shinichi Takagi , Feng Xiao